A three-year campaign by Colorlines.com to get the media to stop using the term “illegal immigrants” scored a tremendous victory on Tuesday when The Associated Press, the nation’s largest news-gathering organization, announced that it was updating news-writing style rules to drop the use of “illegal” when reporting on immigration.

“The discussions on this topic have been wide-ranging and include many people from many walks of life,” the AP blog said. “Earlier, they led us to reject descriptions such as “undocumented,” despite ardent support from some quarters, because it is not precise. A person may have plenty of documents, just not the ones required for legal residence.”

The AP has bureaus in every state capital whose reports fill the nation’s newspapers and are feed local TV news. The change in AP style rules will have tremendous political and cultural impact, said Rinku Sen, president of the Applied Research Center, which publishes Colorlines.com.

“The AP is the last word in fair journalistic standards,” Sen said. “It’s great to see them do the right thing in this instance. Immigrant communities are going to be very excited to have accuracy and humanity restored to coverage of their lives.”

The announcement comes as immigration reform is gaining momentum in Congress and more than three years after Colorlines.com launched “The Drop the I-Word” campaign. It called on the media to stop using the term “illegal immigrant” because it is a racially charged slur that confuses the immigration debate and fuels violence.

“Illegals is a racially charged slur used to dehumanize and discriminate against immigrants and people of color regardless of migratory status,” the campaign’s webpage said. “The i-word is shorthand for ‘illegal alien,’ ‘illegal immigrant’ and other harmful terms.”

ARC and Colorlines.com are a racial justice think tank and home for media and activism. Earlier in its campaign, it convinced seven members of Congress to pledge to drop the i-word, ABC News Univision’s Christina Constantini and Ted Hesson reported.

“It’s worth noting that not all of them have the same ideas about what the future of immigration policy should look like, but they all agree not to use dehumanizing terms as it’s discussed,” Colorlines said. The congressmen include “familiar faces like Rep. John Conyers and Rep. Luis Gutierrez, both of whom have spoken movingly on the House floor about the role that perceptions play in the immigration debate.”

The Associated Press style book is like a dictionary for journalists with the correct use of titles, capitalization, punctuation and other news writing rules.

“The Stylebook no longer sanctions the term ‘illegal immigrant’ or the use of “illegal” to describe a person. Instead, it tells users that “illegal” should describe only an action, such as living in or immigrating to a country illegally,” wrote AP Senior Vice President and Executive Editor Kathleen Carroll on its blog.

“The style guide is the last word on journalistic practice so it’s particularly important for the AP to set this standard,” said Sen. “This should put the debate to rest.”

The updated AP Style Guide entry is being added immediately to the AP Stylebook Online and Manual de Estilo Online de la AP, its new Spanish-language Stylebook.

It now reads as follows: illegal immigration

Entering or residing in a country in violation of civil or criminal law. Except in direct quotes essential to the story, use illegal only to refer to an action, not a person: illegal immigration, but not* illegal immigrant. Acceptable variations include *living in *or *entering a country illegally or* without legal permission.*

Except in direct quotations, do not use the terms illegal alien, an illegal, illegals or undocumented.

Do not describe people as violating immigration laws without attribution.

Specify wherever possible how someone entered the country illegally and from where. Crossed the border? Overstayed a visa? What nationality?

People who were brought into the country as children should not be described as having immigrated illegally. For people granted a temporary right to remain in the U.S. under the Deferred Action for Childhood Arrivals program, use temporary resident status, with details on the program lower in the story.

The Drop the I-Word campaign argued journalists have professional and ethical standards to uphold and that term illegal is not legally or journalistically accurate and it confuses debate.

Margaret Sullivan, The New York Times’ public editor said Monday that her organization is also working on revising its usage of the term “illegal immigrant.”

“On ‘illegal immigrant’: I'm told that @nytimes is also working on revisions to its usage guidelines to ‘provide more nuance and options,’” she tweeted.

Steven Rosenfeld covers national political issues for AlterNet, including America's retirement crisis, democracy and voting rights, and campaigns and elections. He is the author of "Count My Vote: A Citizen's Guide to Voting" (AlterNet Books, 2008).